1. Field of the Invention
This invention relates generally to machines for loading and separating the litter bases normally found in poultry houses.
2. Description of the Prior Art
In the past, machines were employed to remove all of the litter from broiler houses after each batch of chickens reached their desired weight and were taken to market. Today, however, it is preferred to recondition and reuse the litter several times before it is completely removed.
A typical poultry house has a flat dirt floor on which about six inches of litter material, such as sawdust, wood shavings, rice hulls or cut wheat straw, is evenly distributed before starting the baby chicks on feed and water. After six to eight weeks of feeding and watering, the 20,000 to 40,000 birds in the house will have contaminated and encrusted the litter material. Near water fountains, the material is found to be particularly encrusted, because there, the water tends to mix water with the birds' droppings. Other areas, such as poorly drained portions of the floor, areas below roof leaks, and the like, may also experience excessive moisture which produces ammonia when mixed with the droppings and also is a haven for bacteria and disease.
In the past, the house was cleaned periodically by removing all the litter from the floor, and replacing it with fresh litter. In the interim, additional litter was added periodically, and the depth of accumulated used litter would raise the effective floor height substantially between cleanings. There was no practical way to remove only a fraction of the litter in the house, and thus reduce the rate of build-up.
The machine described in U.S. Pat. No. 4,897,183 enabled one for the first time to separate the waste portion of litter from the clean portion. That machine automatically loaded the waste portion into a storage or holding container, while returning the clean portion to the floor of the poultry house. It was provided with two sets of conveyor flights--one solid, one foraminous, to enable one to either pick up all the litter, or to allow part of it (the loose portion capable of passing through the holes in the flights) to return to the floor. Replacing all those flights, however, was a time-consuming chore, and did not allow one to adjust the amount of recycling, other than by alternating the flights in the series. It would have been better to give the operator of the machine the ability to adjust the recycling rate over a substantial range, and to do so quickly.